Phoronix takes a look at the NVIDIA GeForce 400 Fermi Series running under the Nouveau open source driver

With NVIDIA still not providing any open-source support or technical documentation for their graphics processors, for those in the open-source community who seek to use their GeForce 400/500 "Fermi" GPUs without NVIDIA's binary driver, they are left to use the reverse-engineered, community-created Nouveau driver. Fortunately, the support for the NVIDIA Fermi GPUs is coming along at a respectable pace -- with even working OpenGL acceleration -- considering that NVIDIA is providing no support at all. In this article are the first benchmarks of this experimental GeForce 400/500 "Nouveau NVC0" driver versus NVIDIA's official proprietary driver.

  NVIDIA GeForce 400 Fermi Series On Nouveau